384 



FOOD AND DIGESTION 



trypsin, strange to say, is quickly destroyed by the alkaline solution (Bayliss 

 and Starling). The pancreatic juice offers the special case of a secretion of 



FIG. 269. FIG. 270. 



FIG. 269. The Liver from Below and Behind. L. S., Spigelian lobe; L. C., caudate 

 lobe;!,. Q., quadrate lobe; R.L., right lobe;Z.L., left lobe; g. bl., gall-bladder; v.c.i., inferior 

 vena cava; u.f., umbilical fissure; /. d. v., fissure of the ductus venosus; p, portal fissure with 

 portal vein, hepatic artery, and bile-duct. (Wesley, from a His model.) 



FiG. 270. Portion of a Lobule of Liver, a, Bile capillaries between liver cells, the 

 network in which is well seen; b, blood capillaries. X 350. (Klein and Noble Smith.) 



proenzyme which is stable in alkaline solution until acted on by enterokinase. 

 The amount of kinase present will, therefore, markedly influence the 

 amount of digestion of protein per unit of time. 



FIG. 271. Hepatic Cells and Bile Capillaries, from the Liver of a Child Three Months 

 Old. Both figures represent fragments of a section carried through the periphery of a 

 lobule. The red corpuscles of the blood are recognized by their circular contour; vp 

 corresponds to an interlobular vein in immediate proximity with which are the epithelial 

 cells of the biliary ducts. (E. Hering.) 



The Secretions of the Liver. The liver, the largest gland in the body, 

 situated in the abdomen on the right side chiefly, is an extremely vascular 

 organ, and receives its supply of blood from two distant sources, viz., from 

 the portal vein and from the hepatic artery, while the blood is returned from 

 it into the vena cava inferior by the hepatic veins. Its secretion, the bile, 



